Bipolar Electrostatic Chuck for Plasma Dicing Thermal Control
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Solution Overview
Problem
Current methods for dicing semiconductor wafers, such as scribing and sawing, result in chipping, cracking, and waste of wafer real estate due to jagged separation lines and the need for significant spacing between dies, while plasma dicing faces limitations like high costs and production issues with metals like copper.
Innovation Solution
A hybrid method combining laser scribing and plasma etching, using a bipolar electrostatic chuck for temperature control and a substrate carrier with a tape frame, allows for precise cutting and singulation of integrated circuits with minimal heat damage and reduced waste, enabling denser packing and higher yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If scribing or sawing is used for wafer dicing, then the wafer can be separated into individual dies, but chipping and cracking occur along the severed edges and significant spacing must be maintained between dies
Solution Approach 1:
The patent replaces mechanical scribing and sawing systems with a plasma-based dicing system. The plasma etching process uses reactive ions to remove material through chemical reactions rather than mechanical contact, eliminating the chipping and cracking caused by diamond-tipped tools while achieving precise, clean cuts that allow dies to be placed closer together.
Solution Approach 2:
The patent changes the fundamental parameter of the dicing process from mechanical force to plasma energy. By controlling plasma parameters such as power, pressure, and gas composition, the system achieves precise material removal without mechanical contact, improving edge quality and enabling tighter die spacing to increase wafer real estate utilization.
2Manufacturing precision
If plasma dicing is implemented, then cutting precision can be improved, but processing cost increases due to lithography operations
Solution Approach 1:
The patent extracts and eliminates the expensive lithography step from the plasma dicing process. Instead of using lithography to pattern the wafer before plasma etching, the system uses direct plasma dicing with simplified masking, removing the costly lithography operation while maintaining cutting precision through controlled plasma parameters.
Solution Approach 2:
The patent employs disposable adhesive tapes and simple masks that can be easily replaced, eliminating the need for expensive, complex lithography processes. These inexpensive consumables enable precise plasma dicing without the high costs associated with traditional lithography operations, making the overall process more cost-effective.
3Productivity
If plasma processing is applied to metals like copper, then dicing can be performed, but production issues and throughput limits occur
Solution Approach 1:
The patent applies local quality by using selective masking that protects copper regions during plasma dicing. The masking material is applied only in specific areas where plasma exposure would damage copper, allowing the plasma process to proceed through non-copper regions at high speed while protecting sensitive metal areas, thus maintaining both throughput and production stability.
Solution Approach 2:
The patent segments the wafer processing by protecting different regions with selective masking. Copper-containing regions are masked and protected from plasma, while non-copper regions are exposed for dicing. This segmentation allows the plasma process to operate at high throughput on exposed areas without causing production issues in protected metal regions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes chipping and cracking, optimizes wafer space usage, and reduces processing costs by enabling efficient singulation with precise control over temperature and plasma exposure, leading to more dies per wafer and improved manufacturing throughput.
Implementation Method 1
The bipolar electrostatic chuck is configured to control a backside temperature of the substrate carrier prior to and during plasma processing
Implementation Method 2
A plasma source is disposed in an upper region of the plasma etch chamber
Implementation Method 3
A bipolar electrostatic chuck is disposed below the plasma source
Data Source
AI summary
Methods of and apparatuses for dicing semiconductor wafers, each wafer having a plurality of integrated circuits, are described. In an example, a plasma etch chamber includes a plasma source disposed in an upper region of the plasma etch chamber. A bipolar electrostatic chuck is disposed below the plasma source. The bipolar electrostatic chuck is sized to support a substrate carrier having a tape and tape frame. The bipolar electrostatic chuck is configured to control a backside temperature of the substrate carrier prior to and during plasma processing.